摘要
Solid-state lithium-metal batteries based on poly(vinylidene fluoride-co-hexafluoropropylene)(PVH)are frequently proposed to address the detrimental safety issue of conventional lithium-ion batteries by eliminating the use of flammable solvents,but still face a key challenge:low capacity and sluggish charge/discharge rate due to the intrinsic large-gradient Li^(+)distribution across the ionically-inert PVH matrix.Herein,Te vacancies in form of Bi_(2)Te_(3-x) are proposed to polarize the PVH unit to realize efficient decoupling of lithium salts at the atomic level in PVH-based solid polymeric electrolyte.Te vacancies in the PVH electrolyte doped with Bi_(2)Te_(3-x)(PVBT)induce a high-throughput and homogenous Li^(+)flow within the PVH matrices and near the Li metal.Theoretical calculations show that Te vacancies own high adsorption energy with bis(trifluoromethanesulfonyl)imide anions(TFSI^(-)),repulsive effect on Li^(+),and localized electron distribution,giving rise to a lithium-ion concentration gradient of 30 mol m^(-3),the smallest among the PVH-based inorganic/organic composite electrolytes.Consequently,the polarized electrolyte owns an unprecedented high-rate battery capacity of 114 mAh g^(-1)at~700 mA g^(-1)and also superior capacity performances with a cathode loading of 12 mg cm^(-2),outperforming the state-of-art PVH-based inorganic/organic composite electrolytes in Li||LiFePO_(4)battery.The work demonstrates an efficient strategy for achieving fast Liþdiffusion dynamics across polymeric matrices of classic solid-state electrolytes.
基金
supported by Chongqing Technology Innovation and Application Development Special Key Project,CSTB2023TIAD-KPX0010
Chongqing Technology Innovation and Application Development Special Major Project,CSTB2023TIAD-STX0033
Natural Science Foundation of Chongqing,China(CSTB2022NSCQ-MSX0246,CSTB2022NSCQ-MSX1572,CSTB2022NSCQ-MSX0310)
the Science Foundation of National Key Laboratory of Science and Technology on Advanced Composites in Special Environments.
